A probabilistic stress-strain relationship model for steel bars including the non-uniform corrosion effects in chloride environments

An accelerated corrosion test followed by a monotonic tensile test was conducted on 66 groups of steel bar specimens with varying design parameters and the effects of key factors such as corrosion levels, steel bar diameters and corrosion conditions on the non-uniform corrosion and mechanical properties of the steel bars were analyzed emphatically. Based on the test results and probability theory, the non-uniformity of corrosion for corroded steel bars was statistically analyzed, and a probability model of stress-strain relationship of corroded steel bars considering the influences of non-uniform corrosion was further established. The findings indicated that there is non-uniform corrosion along the length of corroded steel bars, which led to irregular corrosion pits on the surface of steel bars. The non-uniformity of corrosion in small-diameter steel bars varies under different corrosion conditions, whereas large-diameter steel bars show little variation in non-uniformity of corrosion across various conditions. The degradation of mechanical properties of steel bars is most notably influenced by the corrosion levels, while the influences of corrosion conditions and the diameters of steel bars on the degradation of the mechanical properties are relatively insignificant. The proposed probability-based model, including the uncertainty effects triggered by the non-uniformity of corrosion, can effectively predict the stress-strain relationship of corroded steel bars based on specified probability requirements. • The non-uniformity of corrosion for corroded steel bars was statistically analyzed based on probability theory. • The influences of non-uniform corrosion on the mechanical properties of steel bars were studied. • The effects of corrosion conditions, rebar diameters, and corrosion levels on the non-uniform corrosion were discussed. • The stress-strain relationship model including non-uniform corrosion effects of corroded steel bars was established.